Energy for desalination of saline water and brackish groundwater - A case study of the Metropolitan Region of Recife

The world is undergoing changes and the goals of sustainable development are the parameters to guide energy transition choices towards a development that seeks to mitigate anthropic impacts. In this context, the present work is of importance, as it sheds light on knowledge about an inseparable Brazilian link and objectives 6 - clean energy and 7 - access to quality water of the UN’s sustainable development. The water and energy nexus is strongly related in Brazil, because for the production of groundwater, energy is used mostly from hydroelectric plants and for energy production, water from dams is used, which are also impacted by the volume of groundwater. However, climate change is putting pressure on the already delicate balance and positioning of the saline wedge in the coastal region. We adopted the Metropolitan Region of Recife as a case study. If we had the opportunity to supply the entire population of 3 million inhabitants with desalinated saline water, an installed capacity of 103MW would be required. And in order to bring the waters that are already saline on the coast of the MRR to potability standards and supply only groundwater to the population, an installed capacity of 9.5MW would be required. However, every rise in sea level and also overexploitation can increase the salinity of the wells, making desalination not the only alternative to be considered, but it should be strongly considered as an alternative, especially when it is accompanied by sustainable energy, such as wind or photovoltaic.